Heating flanges of the generic kind are principally used for heating the flow of intake air in an intake line leading to an internal combustion engine. They are especially used in diesel engines in order to make a cold start easier.
In DE 105 15 533 C2, a heating flange is described in which a heat conductor running in a meandering shape is mounted on a carrier rod. The heat conductor is, however, only mounted on the carrier rod in the middle of the straight meandering turns, but not on the reversements of the meandering. As a result, it can be that, given the strong vibrations to which a heating flange is exposed in an intake line leading to an internal combustion engine, contacts of adjacent heat conductor reversements result, leading to a short circuit.
This problem is remedied in WO 99/53187 A1 by having the reversements of the heating meander placed in two holding devices. The two holders are connected to one another and arranged opposite one another, so that the straight sections of the heating meander run parallel between the two holders.
In WO 00/34643 A1, a further development of WO 99/53187 A1 is described in which the holding devices arranged in parallel are attached to two opposite walls of a closed frame of the heating flange.
However, the problem that occurs with both WO 99/53187 A1 and WO 00/34643 A1 is that the heat conductor cannot be fixedly mounted to the holders or the frame because the heat conductor and the frame expand to different degrees during the operation of the heating flange. For this reason, the holders of the heat conductors are principally mounted to the frame via a spring element, which compensates for the various linear expansions, such as is described in WO 99/53187 A1, WO 00/34643 A1 or also DE 102 57 921 B3, for example.
A fixed connection of the heat conductor to the frame with simultaneous cushioning bearing of the heat conductor for balancing the different linear expansions is achieved in the apparatus of DE 102 14 166 A1 by an angled form of the meander coil leg pieces. The heating flange of DE 102 14 166 A1 comprises a closed basic body with a retaining clamp and, fixedly connected to the closed basic body, a heating element that is arranged as a meander coil.